Interleukin 4 (human IL4, UniProt P05112) is a 129 amino acid cytokine derived from T cells and mast cells with multiple biological effects on many cell types including B-cells, T-cells and nonlymphoid cells including monocytes, endothelial cells and fibroblasts. IL4 is a pleiotropic cytokine and has been implicated in many of the cellular responses associated with asthma including IgE production, inflammation, airway hypersensitivity, and goblet cell hyperplasia (Perkins, et al., J Allergy Clin Immunol 118: 410-9, 2006; Pene, et al., Proc Natl Acad Sci USA 85: 6880-4, 1988). Its production by both T-cells and mast cells is regulated by a variety of mediators and cytokines that sustain Th2-mediated responses. IL4 signaling is mediated via two receptor complexes, the Type I receptor complex and the Type II receptor complex. Signaling through the type II receptor complex, composed of one IL-4Rα and one IL13Rα1 chain, is largely responsible for the shared biological effects of IL4 and IL13 and both IL4 and IL13 may contact the components of the complex. The type I receptor complex, comprised of the IL-4Rα and common γ-chain is, exclusively responsive to IL4 and mediates IL4 responses in T-cells which do not express IL13αR1 (Idzerda, et al., J Exp Med 171: 861-73, 1990; Nelms, et al., Annu Rev Immunol 17: 701-38, 1999).
Neutralizing the effects of IL4 using antibodies or as demonstrated by the responses of IL4 deficient mice, inhibits allergen-specific IgE and reduces eosinophilia (Zhu and Paul, Blood 112: 1557-69, 2008), as well as airway hyperresponsiveness (AHR) (Heaton, et al., Lancet 365: 142-9, 2005) in murine models of TH2 inflammation. Similarly, soluble IL4 receptor has been used to inhibit IL4 signaling and has been shown to reduce allergen-induced AHR as well as VCAM-1 expression, mucus production and eosinophil recruitment to the lungs of mice (McKinley, et al., J Immunol 181: 4089-97, 2008). In human cells, IL4 has been shown to drive the differentiation of naïve T helper (Th0) lymphocytes into TH2 lymphocytes (Breekveldt-Postma, et al., Curr Med Res Opin 24: 975-83, 2008; Wraight, et al., Respirology 7: 133-9, 2002). TH2 cells have been shown to secrete IL-4, IL-5, IL-9 and IL13 but do not produce IFNγ, contributing to an imbalance of pro-inflammatory TH2 cytokines (Partridge, Ann Oncol 17: 183-4, 2006). Neutralization of IL4 with antibodies that inhibit receptor binding blocks T-cell differentiation ((Idzerda, et al., J Exp Med 171: 861-73, 1990; Nelms, Keegan et al., Annu Rev Immunol 17: 701-38, 1999)). Polymorphisms in the genes encoding IL4, IL4Ra, and IL13 have been associated with asthma, in fact, both IL4 and IL4Rα polymorphisms are associated with severe asthma and exacerbations of asthma (Sandford, et al., J Allergy Clin Immunol 106: 135-40, 2000; Wenzel, et al., Am J Respir Crit Care Med 175: 570-6, 2007). Based on the perceived central role of IL4 in asthma, biotherapeutics that inhibit the activity of IL4 were expected to be valuable tools for the treatment of asthma and other Th2-associated pathologies. However the results of clinical studies using a soluble IL4 receptor were disappointing and showed minimal differences in the incidence of asthma exacerbations between placebo and treatment groups (Borish, et al., J. Allergy Clin. Immunology 107: 963-70, 2001).
Like IL4, Interleukin 13 (IL13) is cytokine identified from activated human T lymphocytes. Over the last 10 years, a variety a reports have demonstrated a role for IL13 in many of the cellular responses associated with asthma including IgE production, inflammation, airway hypersensitivity, mucus production and lung fibrosis (Kasaian and Miller, Biochem Pharmacol 76: 147-55, 2008). Its production is regulated by a variety of mediators and cytokines that interact in a positive feedback loop to sustain Th2-mediated immune responses. IL13 signaling is predominantly mediated via the Type 2 receptor, IL13α1 and IL-4Rα complex. The Type 2 complex, when present, is also activated by IL4 binding (Wills-Karp, Immunological Reviews 202: 175-90, 2004; LaPorte, et al., Cell 132: 259-72, 2008). IL13Ralpha2, is a receptor capable of high affinity binding of IL13 and may play a more functional role either by attenuation of the actions of IL13 and IL4 or via induction of TGF-beta and development of lung fibrosis.
A variety of in vivo data supports a role for IL13 in the pathogenesis of asthma. In cynomologus monkey models of allergic respiratory disease, antibodies that block the action of IL13 have been shown to reduce lung inflammation (Kasaian, et al., J Pharmacol Exp Ther 325: 882-92, 2008). In humans, increased IL13 levels can be measured in the bronchial tissue, nasal lavage flurid, and induced sputum from asthmatic patients. Genetic polymorphisms that are associated with asthma have been identified at the IL13 locus (Heinzmann, et al., Hum Mol Genet. 9: 549-59, 2000). In addition, IL13 appears to play an important role in other atopic diseases including dermal fibrosis and atopic dermatitis. Antibodies or other protein molecules that inhibit the activity of IL13 may be valuable therapeutics for the treatment of asthma and other atopic diseases (Brightling, et al., Clin Exp Allergy 40: 42-9).
Taken together, the in vivo and in vitro data for IL13 and IL4 suggest that therapeutics that can inhibit the actions of both cytokines may be efficacious agents for the treatment of asthma.
The technical problem underlying the present invention is to identify novel IL-4 and IL-13 antagonists (e.g., neutralizing binders) which can be used alone or in combination for an improved treatment of inflammatory disorders, cancer, atopic diseases and other pathological conditions associated with allergic or atopic responses, e.g., asthma, eosinophilia, and fibrotic conditions and where pulmonary functions are affected, to provide for local delivery of an IL4, IL-13, or an IL4 and IL13, neutralizing molecule.